ExperimentsThe experiments below are experiments suggested by Edexcel. There is the expectation that you understand these experiments. We will carry out most of these experiments but will not be able to do all of them.
For most experiments there is a link to the instructions for the experiment. For some experiments there is a page number of where the experiment is described in your Edexcel IGCSE Chemistry student book. For others there is a link to a video clip or a brief description.
You will notice that you need to be able to describe some of the experiments which means that you could be asked how you will carry out the experiment i.e. the main steps (no need to include amounts). For those experiments, the learning objective (in red) has been included in the box.
1b
1.4 Describe and explain experiments to investigate the small size of particles and their movement including (i) dilution of coloured solutions and (ii) diffusion experiments
Dilution of a coloured solution: Using a 100 ml measuring cylinder you take 10 ml form a coloured solution and add 90 ml water to the 100 ml mark. This is a 10x dilution. Now take 10 mol from the diluted solution and add again 90 ml of water. This is again a 10 x dilution but a 100x dilution of the original solution. Continue this process until you cannot see any colour anymore.
1.7 Describe experimental techniques for the separation of mixtures, including simple distillation, fractional distillation, filtration, crystallization, and paper chromatography. This means writing down the details how to carry out the experiment and explaining how the components are separated and on which property this technique relies.
Evaporate a solution to dryness to determine the mass of solute in a given mass of solution: measure the mass of an evaporating basin, add the solution, measure the mass of the basin and solution, evaporate the solution to dryness, measure mass again until constant (i.e. no more decrease), do the necessary subtractions i.e to find the mass of the solution and the mass of the solute .
Investigate mass changes before and after the reaction of e.g. copper sulfate and sodium carbonate: Investigating mass changes in chemical reactions.doc. This investigation uses lead nitrate and potassium iodide but the principles are the same as using copper sulphate and sodium carbonate.
1.23 Understand how the formulae of simple compounds can be obtained experimentally, including metal oxides, water and salts containing water of cystalization (=hydrated salts)
Finding the empirical formula of magnesium oxide: MgO formula.doc
Determine the formula of a hydrated salt such as barium chloride or copper sulfate by heating to drive off water of crystallisation: finding the formula of a hydrated salt.doc
Prepare a substance and calculate the % yield, given the theoretical yield: remember % yield = actual yield (mass of the substance prepared/theoretical yield x 100): Calculating percentage yield.doc
Determine the molar volume by measuring the volume and mass of a gas using a heavier gas (e.g. carbon dioxide): the mass of a heavy gas can be measured by measuring the mass of an empty gas syringe, add the gas and measure the mass again and subtract the mass of the empty cylinder; use the gas syringe to also measure the volume of the gas. Convert the mass of the gas into number of moles. Divide the volume by the number of moles to obtain the molar volume.
Acid and alkali titrations - titrations can also be used to find the unknown concentration of an acid or alkali: acid-base titration.pdf
1f, g and h
Classify different types of elements and compounds by investigating their melting points and boiling points, solubility in water and electrical conductivity (as solids and in solution) including sodium chloride, magnesium sulfate, hexane, liquid paraffin, silicon(IV) oxide, copper sulfate, and sucrose (sugar)
1.53 Describe experiments to investigate electrolysis using inert electrodes (e.g carbon), of aqueous solutions such as sodium chloride, copper (II) sulphate and dilute sulfuric acid and predict the products.
Investigate properties of metals: simple experiments to investigate electrical and thermal conductivity
the reactions of calcium compounds: the decomposition of calcium carbonate and the reaction of calcium oxide with water; the reaction of calcium carbonate with acid: decomposition of calcium carbonate is carried out in "Thermal stability of carbonates" in 2f and reaction of calcium carbonate with acid in "Reactions of acids" in 4a.
Carry out an activity to show that transition metal salts have a variety of colours: well, take some transition metal compounds and look at them.
2b
2.6 Describe the reactions of the alkali metals with water and understand that the reactions provide a basis for their recognition as a family of elements.
Dissolving hydrogen chloride in water and methyl benzene: Blue litmus goes red in hydrogen chloride dissolved in water as the hydrogen chloride has dissociated and hydrogen ions have been formed making hydrochloric acid. The blue litmus remains blue when hydrogen chloride dissolves in methyl benzene as it does not dissociate and therefore not form any hydrogen ions.
Halogens reacting with iron wool: the more reactive the halogen the more vigorous the reaction. Watch this video clips:halogens and iron wool
2d
2.17 Explain how experiments involving the reactions of elements such as copper, iron and phosphorus with air can be used to determine the percentage by volume of oxygen in air.
Investigate the volume of air used up and products formed when candles are burned: watch this clip
2.18 Describe the laboratory preparation of oxygen from hydrogen peroxide using manganese (II) oxide as catalyst
Laboratory preparation of oxygen: catalytic decomposition of hydrogen peroxide. - page 47 and 55.
2.20 Describe the laboratory preparation of carbon dioxide from calcium carbonate and dilute hydrochloric acid.
Making carbon dioxide: page 59.
Method collecting gases: page 92.
2.19 Describe the reactions with oxygen in air of magnesium, carbon and sulphur, and the acid- base character of the oxides produced.
Burning elements in oxygen: see handout section 2d: oxygen and oxides.
2.21 Describe the formation of carbon dioxide from the thermal decomposition of metal carbonates such as copper(II) carbonate.
The thermal decomposition of copper (II) carbonate: see "Thermal stability of carbonates" in 2f.
2e
2.25 Describe the reactions of dilute hydrochloric acid and dilute sulfuric acid with magnesium, aluminum, zinc and iron.
Making hydrogen using metals and acids: see "Reactions of acids" in section 4a; a reaction with an acid and a metal reactive enough produces a salt and hydrogen - page 73.
2.27 Describe the use of anhydrous copper (II) sulphate in the chemical test for water.
2.30 Describe how reactions with water and dilute acids can be used to deduce the following order of reactivity: potassium, sodium, lithium, calcium, magnesium, zinc, iron and copper.
Investigate properties of metals (also 2a).
Reactions of metals with acids: see "Reactions of acids" in 4a.
Reactions of metals with water: page 65.
Investigate the reactions of calcium compounds: the decomposition of calcium carbonate and the reaction of calcium oxide with water; the reaction of calcium carbonate with acid (also in 2a).
Competition for oxygen between metals (e.g thermite reaction)(redox reactions): Competition for oxygen.pdf
Investigate the ease of thermal decomposition of carbonates, including calcium carbonate, zinc carbonate and copper carbonate: Thermal stability of metal carbonates.pdf
Causes and prevention of rusting of iron: Rusting.pdf
2g
2.37/2.38 Describe the tests for cations and anions 2.39 Describe tests for gases:
Making dry samples of insoluble salts: see "precipitating salts" above and in your handout section 4a.
Test predictions of whether a precipitate forms when soluble salts are combined: know your solubility rules!
4b
4.11 Describe simple calorimetry experiments for reactions, such as combustion, displacement, dissolving and neutralisation in which heat energy changes can be calculated from measured temperature changes.
Measurement of enthalpy change (displacement reactions; combustion)(compare the temperature rise produced when the same volume of water is heated by different fuels): Heat of neutralization.pdf and combustion of fuels.pdf
4c
4.17 Describe experiments to investigate the effects of changes in surface area of a solid, concentration of solutions, temperature and the use of a catalyst on the rate of a reaction.
Investigate the fractional distillation of ‘artificial crude oil’ and the ease of ignition and viscosity of its fractions.
5.14 Describe how long-chain alkanes are converted to alkenes and shorter-chain alkanes by catalytic cracking, using silica or alumina as the catalyst and a temperature in the range of 600–700°C.
For most experiments there is a link to the instructions for the experiment. For some experiments there is a page number of where the experiment is described in your Edexcel IGCSE Chemistry student book. For others there is a link to a video clip or a brief description.
You will notice that you need to be able to describe some of the experiments which means that you could be asked how you will carry out the experiment i.e. the main steps (no need to include amounts). For those experiments, the learning objective (in red) has been included in the box.
- Dilution of a coloured solution: Using a 100 ml measuring cylinder you take 10 ml form a coloured solution and add 90 ml water to the 100 ml mark. This is a 10x dilution. Now take 10 mol from the diluted solution and add again 90 ml of water. This is again a 10 x dilution but a 100x dilution of the original solution. Continue this process until you cannot see any colour anymore.
- Diffusion of NH3(g) and HCl(g): Diffusion in gases.pdf - book p4.
- Diffusion in liquids.pdf
1.7 Describe experimental techniques for the separation of mixtures, including simple distillation, fractional distillation, filtration, crystallization, and paper chromatography. This means writing down the details how to carry out the experiment and explaining how the components are separated and on which property this technique relies.- Investigate mass changes before and after the reaction of e.g. copper sulfate and sodium carbonate: Investigating mass changes in chemical reactions.doc. This investigation uses lead nitrate and potassium iodide but the principles are the same as using copper sulphate and sodium carbonate.
1.23 Understand how the formulae of simple compounds can be obtained experimentally, including metal oxides, water and salts containing water of cystalization (=hydrated salts)- Check the test on electrical conductivity in
Investigating properties of ionic solids.doc
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- valent compounds.
1.53 Describe experiments to investigate electrolysis using inert electrodes (e.g carbon), of aqueous solutions such as sodium chloride, copper (II) sulphate and dilute sulfuric acid and predict the products.2.18 Describe the laboratory preparation of oxygen from hydrogen peroxide using manganese (II) oxide as catalyst
2.20 Describe the laboratory preparation of carbon dioxide from calcium carbonate and dilute hydrochloric acid.
2.19 Describe the reactions with oxygen in air of magnesium, carbon and sulphur, and the acid- base character of
the oxides produced.
2.21 Describe the formation of carbon dioxide from the thermal decomposition of metal carbonates such as
copper(II) carbonate.
2.27 Describe the use of anhydrous copper (II) sulphate in the chemical test for water.
2.39 Describe tests for gases:
temperature of about 30°C
3.12 Describe the dehydration of ethanol to ethene, using aluminium oxide.
4.7 Describe experiments to prepare soluble salts from acids
4.9 Describe experiments to carry out acid-alkali titrations
4.8 Describe experiments to prepare insoluble salts using precipitation reactions
5.14 Describe how long-chain alkanes are converted to alkenes and shorter-chain alkanes by catalytic cracking,
using silica or alumina as the catalyst and a temperature in the range of 600–700°C.